Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. Now a company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning.
When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard’s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies.
Poseidon keeps watch through a network of underwater and overhead video cameras. AI software analyses the images to work out swimmers’ trajectories(轨迹). To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool.
It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory.
To pick out potential drowning victims, anyone in the water who starts to descend(下降)slowly is added to the software’s “pre-alert” list, says McQuade. Swimmers who then stay immobile on the pool bottom for five seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures(使模糊) the pool’s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer’s location on a poolside screen.
The first full-scale Poseidon system was officially opened at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools—and he was once an underwater escapologist(脱身杂技演员) with a circus. “I say full marks to them if this works and can save lives,” he says.
【小题1】The underlined word “monitoring” in paragraph 2 is closest in meaning to “________”.| A．advertising | B．training | C．maintaining | D．watching |
| A．It must be able to descend in the water. |
| B．It must be able to videotape every movement. |
| C．It can distinguish between a swimmer and a shadow. |
| D．It can save a life within a few months. |
| A．It orders an underwater robot to rescue the drowning swimmer. |
| B．It alerts the lifeguard. |
| C．It displays the swimmer’s shadow on the screen. |
| D．It watches the pool through dozens of overhead cameras. |
| A．He owns a swimming pool. | B．He invented the clockwork radio. |
| C．He was once an entertainer. | D．He runs a company. |
